Hesitation in acceleration

Recently I started to notice a small hesitation during accelration, epically when shifting from full elect to hybrid drive (engine + elect) or when going from the first half of the Eco bar to the second bar
I tried to drive using normal and Eco mode same things happens,
Checked my Car using OBD also there is no code
Today the hesitation was noticeable like the car is losing power to move, it was during a traffic jam, and I was driving below the in the first half of the Eco bar, and after the battery left with 2 bar this happened when the car started the engine to charge the battery
Car odo meter is 115k mile
Changed the spark plug last year with oem ones
Oil changed before 3 months

 

Battery health is good, Air filter changed last year, how to check. The throttle body,
By the way never did a fuel system cleaning before which includes the injectors, throttle body and etc

 

I already used last Thursday compress air to clean it, and it was soooo dusty

 

got them from the service center (official one for Toyota in country) battery cooling fan to be honest no i haven't checked, during this summer i have noticed that there's a hovering sound from the engine when i am climbing a long steep road, and when i remove my feet from the pedal the sound like the engine is calming down